I just got an A7s yesterday and have been testing various settings on the camera to see how I'd like to set it and use it for the foreseeable future. One thing I'd like to share is that I've discovered that Silent Shooting Mode results in significantly poorer low light performance compared to when using the shutter. I've tested this from ISO 6400 and up. Would be interested in knowing other people's thoughts on this and why it may be. Keep in mind, I'm not a pro tester. I'm just a photographer.